Novel junction design for NMOS Si Bulk-FinFETs with extension doping by PEALD phosphorus doped silicate glass

We demonstrate a NMOS Si Bulk-FinFET with extension doped by Phosphorus doped Silicate Glass (PSG). Highly doped PSG (6e21 cm^-3) was used as a diffusion source. SiO₂ cap on PSG decreased sheet resistance (Rs) due to less out diffusion of P. Even when thin SiO₂ exists at the interface between Si and PSG, P diffused from PSG into Si. Thanks to the high etch rate of the PSG/SiO₂ cap stack after drive-in anneal, the PSG/SiO₂ cap was successfully removed by HF with minimum removal of STI and gate hard mask oxide. PSG provides damage free and uniform sidewall doping to fin. On current I_ON is improved by 20% for L_G in the 30-24 nm range, with similar I_OFF and better DIBL compared to P ion implanted reference.